The Effects of Ultraviolet (UV) Radiation on the Eyes
Ultraviolet (UV) radiation from the sun can cause sunburn and skin cancer. Aside from the skin, the eyes are at risk, too. Damage linked to extended sun exposure include macular degeneration, cataracts, photokeratitis and pingueculae and pterygia. The October 2008 issue of Archives of Ophthalmology said the sun’s high energy visible (HEV) radiation known as blue light may potentially increase risks of macular degeneration and also cause retinal damage to persons with poor blood plasma levels of vitamin C and other antioxidants.
Protect your eyes by using a pair of sunglasses that fully blocks UV and HEV rays. Wraparound style sunglasses with 100% UV protection that can shield your eyes from all sides provide the utmost protection. Also, make it a habit to wear wide-brim hats for added protection.
UV light is actually invisible high-energy rays divided into three categories.
With wavelengths of 100-280 nanometer, UVC rays are the highest energy form that could be most dangerous to the skin and the eyes. While it is blocked by the ozone layer, the depletion of the ozone has allowed more UVC rays to penetrate the atmosphere, increasing the risks of UV-related health issues.
Compared with UVC, these are lower energy rays with wavelengths of 280-315 nm and are also blocked by the ozone layer but not fully. Light exposure to it promotes melanin production, pigments that darken the skin. Extended exposure in higher doses increases the risks of premature skin aging, discoloration and skin cancer.
These are comparatively low energy rays similar to visible light rays but can go through the cornea, the lens and the retina of the eyes.Too much exposure could lead to cataracts and the development of macular degeneration.
Overexposure to UV radiation has been known to cause numerous eye problems such as:
Pingueculae and Pterygia – is an ugly growth on the eye surface suspected to be caused by long-term UVB rays exposure. Vision may be impaired due to corneal problems associated with the condition.
Photokeratitis also known as snow blindness is a temporary loss of vision due to an inflammation of the cornea which is very painful. Short-term UVB rays exposure can cause this condition which lasts from 24 to 48 hours. Protect your eyes from this condition with UV-blocking sunglasses wherever there is snow especially when at high altitudes.
Cataracts and Macular Degenerationare eye conditions linked to UVA exposure. UVB rays are not known to cause them as this UV radiation type is absorbed by the cornea.
Visible HEV radiation (blue light) has lower energy and longer wavelengths of 400-500 nm but can still penetrate the eyes and cause harm to the retina. Avoid the eye risks and problems posed by UV and HEV radiation exposure by taking precautions especially if you spend time outdoors. The risk factors include:
- Location – the risks are higher in tropical areas nearer the equator.
- Altitude the higher the elevation, the higher the UV levels.
- Sun setting 10a.m. to 2p.m.is the time the sun is at its hottest producing greater UV and HEV levels.
- Surrounding there are less levels of harmful rays in places dense with tall structures compared with more exposed areas (snow and sand for instance) where levels are twice as much.
- Medications people taking medications like birth control pills and some anti-biotics are more sensitive to UV and HEV rays.
Note that the risks are the same even during overcast days as UV rays can still penetrate clouds. You just can’t see them.
Provide Better UV Protection for Kids
The skin and eye damage risk increases as more time is spent under the sun. In a lifetime, about 50% of UV rays exposure happens before reaching the age of 18 because as kids, people spend more time outdoors. That is why it is important to give children more and better protection.
Children’s eyes have to be protected with quality sunglasses. In addition to this, have your kids wear hats during sunny days for added defense against UV exposure.
Sunglasses to Look For
Kids or adults are better off wearing good quality sunglasses when outdoors especially when the sun is high. Ask your optician to help you find a pair that has 100% UV and HEV rays protection. Choose a close-fitting wraparound type with large lenses to cover as much delicate skin around the eyes. Performance or sport sunglasses are recommended for active people who love exploring the outdoors.
Do Lens Colour Matter?
Yes for HEV protection, not for UV protection. Dark gray or light amber coloured lenses provide the same UV protection but go for darker lenses if you wish to block a significant amount of blue light. Seek the help of your optician when choosing sunglasses that cater to your specific purpose.
Reduce UV and HEV exposure by 50% by wearing wide-brimmed hats on a particularly sunny day.
Additional tips on proper eye protection from the sun:
- Not every pair of sunglasses can give 100% protection. With the use of instruments like spectrophotometers (it measures how much UV and HEV radiation lenses can block), an eye professional can help evaluate your sunglasses. Most sunglasses can block some HEV rays but more are blocked by those with bronze, copper or red-brown lenses.
- Staying under the shade reduces but does not stop UV or HEV rays from damaging your eyes. These rays bounce back from other surfaces so continue wearing sunglasses even when under the shade.
- Being in the snow does not mean there is no UV radiation exposure. In fact you are exposing yourself twice as much because 80% of UV rays can be reflected by the pure whiteness of the snow. Reduce exposure by wearing ski goggles with adequate UV protection.
- Sunglasses are still needed even if you wear UV ray blocking contact lenses. Without sunglasses, some areas of the eye may still be harmed such as the conjunctiva and other delicate skin area around the eyes. Contact lenses can only cover the certain eye parts.
- Protect your eyes and wear sunglasses because darker skin and eyes do not free you from the dangers of skin cancer and other eye problems brought about by UV rays.
The sun may pose a lot of dangers to the skin and the eyes cause by UV rays but that is not to say stop enjoying the outdoors. You can always protect yourself against these dangers by wearing proper covers, sunscreens and sunglasses.